Do you implement intrusive practices like google and facebook in that you try to almost stalk them?
To answer this I would give you a little of my background CPA theory.
I always like to divide a business into 3 tiers
Tier 1, tier 2 and tier 3.
Tier 3 is the lower, the "starter" process, where you start creating your business and start receiving your visits (0-50K MAU)
Tier 2, is where you start to consolidate (50-500K MAU)
Tier 1, is where it has fully bloomed (500K+ MAU just an orientation, it will be much less, like 1/10x for certain industries that are more item exclusive)
I've worked for several years in the 3 tiers. And these are my conclusions:
This kind of data is only valid for tier 1. The amount of processes involved in tier 2 and tier 3 businesses is so extremely high, that it completely eclipse this data analysis work.
For example, branding, similarly to data analysis for CPA is only reserved for Tier 1 businesses. Many people ask in this forum about branding when they have not even reached Tier 2.
Also, there are different players in each tier. Most people in this kind of forums, are always around Tier 3 and Tier 2. Because blackhat techniques are generally growth hacking tools to start fast and furious but decay over time. Any fully bloomed a consolidated business in Tier 1 will not profit much from BH techniques but other things like the ones you comment here (data analytics, data mining and crossing inputs).
Obviously if you are doing FB/GAds or any kind of advertisement, this data retrieved from OTHERS (massive amounts of data 1M MAU at minimum),
it's 100% needed. But not from your site (except for the cookie conversion to show in the FB/GAds analytics).
Using analytics data to start the campaign just from your own site, is completely useless on lower tiers (unless you could use it for filtering down, for example, remove all leads outside Minnesota, or remove all leads with age 21 or under for certain campaign where you are selling a very localized product or an adult-only product that just arrived to your stock).
But for example, trying to identify which "sub-group" generates more conversion just by reading my lead list in a Tier 2/3 ecommerce is a 100% waste of time.